Category: Hiv prevention

While a standard course of post-exposure prophylaxis (PEP) requires taking medication for a full 28 days, experts estimate that the active drugs are out of your system within 24 to 48 hours after the final dose. This guide explains the science behind **how long does PEP stay in your system** and the pharmacological factors that influence its clearance.

According to the CDC, post-exposure prophylaxis (PEP) can reduce the risk of HIV infection by more than 80% when taken correctly. To achieve this, PEP involves a combination of powerful antiretroviral drugs that must be started within 72 hours of a potential exposure. Understanding what drugs are part of PEP is the first step in seeking this emergency prevention method.

When taken consistently, PrEP reduces the risk of getting HIV from sex by about 99%. However, a number of factors, including poor medication adherence, starting PrEP with an undetected HIV infection, and transmitted drug resistance, can all cause PrEP to fail.

According to the DISCOVER trial, switching from Truvada to Descovy for pre-exposure prophylaxis (PrEP) led to measurable improvements in markers of kidney function and bone mineral density. This evidence highlights the distinct pharmacological profiles of these two antiretrovirals, which is a primary reason why some individuals and their healthcare providers consider a switch from Truvada to Descovy.

PEP must be initiated within 72 hours of potential HIV exposure, but modern guidelines confirm that tenofovir alone is not enough for PEP, and recommend combination therapy for post-exposure prophylaxis. This is a critical development in preventing HIV infection after exposure.

The list price for Apretude, the injectable form of cabotegravir for PrEP, is approximately $4,125 per dose, which is administered every two months [1.2.1, 1.2.3]. This article breaks down the factors influencing the final answer to 'How much does cabotegravir cost?'.

When taken as prescribed, both Descovy and Truvada are about 99% effective at preventing HIV from sexual exposure [1.2.2, 1.3.3]. The debate over the question, **Is Descovy better than Truvada?**, centers on their different side effect profiles and approved uses.

According to the IPERGAY trial, the 2-1-1 rule for tenofovir, an intermittent PrEP regimen, showed 86% effectiveness in preventing HIV transmission among men who have sex with men (MSM). This alternative to daily dosing offers a different approach to pre-exposure prophylaxis for individuals who can anticipate their sexual activity.

Following its FDA approval in June 2025, Yeztugo (lenacapavir) became the first and only twice-yearly injectable option for HIV pre-exposure prophylaxis (PrEP) in the United States. For those asking, 'Is Yeztugo available?', the answer is yes in the United States, representing a significant advancement in HIV prevention by simplifying the dosing schedule and addressing adherence barriers.